EP2689112B1 - Mechanically controllable valve drive and mechanically controllable valve drive arrangement - Google Patents

Description

The invention relates to a mechanically controllable valve drive with a gas exchange valve, which acts directly or indirectly on a transmission arrangement by means of a working contour, wherein the transmission assembly is movably mounted in the cylinder head by means of bearing and wherein the transmission assembly is in operative connection with a Ventilhubverstelleinrichtung and a camshaft, wherein the Ventilhubverstelleinrichtung a rotatable adjusting shaft, such that different maximum strokes are adjustable, wherein the transmission arrangement has a first and a second Radorgan, wherein the first Radorgan is in operative connection with the camshaft and the second Radorgan directly or indirectly the gas exchange valve acts, both Radorgane on the Adjusting shaft are rotatably mounted and have a toothing, such that the first and the second wheel member are so geared together, that an adjustment of the adjusting a phase nverschiebung between the first and the second Radorgan causes and that a rotational fixation causes an oscillating movement of the first and second Radorgans.

A valve gear and a valve train arrangement are for example from the EP 638 706 A1 known. Here, an eccentric shaft rotatably mounted in a cylinder head is provided for controlling or regulating the valve lift, which acts on the transmission arrangement such that in a simple way valve strokes between 0 and maximum can be set. By this measure, the combustion process can be easily adapted to the respective operating state of the internal combustion engine.

In addition, it is from the DE 10 2004 003 324 A1 It is known to provide adjusting members in a valve train arrangement which can be adjusted independently of each other with the aim of resting individual cylinders for certain operating conditions. Furthermore, from the EP 1 760 278 A2 a valve train known, which has an eccentric member having different curves, in particular for the partial stroke and the full stroke. A zero-stroke curve is also made possible by the adjustment.

From the DE 10 2006 035 391 A1 is a generic mechanically controllable valve train is known in which a displacement of two Radorganen each other causes a phase shift of the Radorgane each other and thereby cause a valve lift.

However, these known valve trains / valve train arrangements have the disadvantage that an adjustment of the valve lift takes place via a translational and rotational movement of an intermediate lever of the transfer arrangement. As a result, a very complicated guide of the intermediate lever must be used, combined with tight manufacturing and assembly tolerances. Overall, this results in an expensive and difficult to control overall construction of the transmission arrangement.

This valve train has the disadvantage that an adjustment requires a lot of effort. As a result, increased wear and a complex design of actuators is given.

The object of the invention is therefore to provide a valve train or a valve train arrangement which avoids the above-mentioned disadvantages.

The object is achieved in that the toothing is designed such that a rotation of the adjusting causes the phase shift. As a result, a mechanical valve train is created, which is designed so that only a rotational movement is required to ensure a valve lift. As a result, a much simpler storage of the transmission arrangement is possible and wear phenomena could be substantially minimized.

A particularly advantageous embodiment is provided in that the first wheel member is biased by a spring element with respect to the camshaft. This also makes it possible that the adjusting shaft can be driven in both directions. Also games can be compensated in the gearing.

A first, particularly advantageous embodiment of the invention is provided by the fact that the first and the second Radorgan are designed as mutually facing crown gears and the geared connection is made via at least one planetary gear, each planet gear is mounted on a rotatably connected to the adjusting shaft axis , This embodiment is designed as a crown gear planetary gear.

A second, particularly advantageous embodiment of the invention is characterized in that the first and the second wheel member are formed as internal gears, wherein the first wheel member has a different inner diameter with a different number of teeth than the second wheel member and that the adjusting shaft has an eccentric rotatable on the a first and a second spur gear are mounted, which are rotationally rigidly coupled to each other and which are respectively in engagement with the first and second Radorgan and thus establish the geared connection. With such an embodiment can easily in the case of a design with less Number of teeth difference between the first and second Radorgan a high reduction of the adjusting against the phase shift between the first and the second Radorgan be prepared. By this high, internal reduction only a small Aktuatorkräfte for driving the adjusting shaft are required and on the other hand, a very accurate adjustment of the maximum valve lift the gas exchange valves possible. In this case, it is particularly advantageous in terms of assembly and production if the first and the second spur gears are made in one piece. A particularly compact designed mechanically controllable valve drive is created in that the second wheel member is rotatably mounted on the peripheral surface of the first wheel member.

It is also advantageous if the first wheel member has a contact roller for the camshaft, so that the first wheel member is set by the continuously rotating camshaft in an oscillating rotation about the axis of the adjusting shaft. The second wheel member can be designed in an advantageous manner such that it has the working contour.

In a third, particularly advantageous embodiment of the invention, the second Radorgan geared to a working contour having deflection member is connected, wherein the Auslenkorgan is rotatably and concentrically mounted on the camshaft. It is particularly advantageous assembly and production technology, when a drag lever is rotatably mounted on the adjusting shaft. In this way, a pre-testable, easy-to-install unit of transmission assembly and drag lever can be created.

The object is likewise achieved by a mechanically controllable valve drive arrangement in which each cylinder is assigned a mechanically controllable valve drive according to one of claims 1 to 10, wherein each gas exchange valve is assigned in each case a working contour which acts directly or indirectly on the gas exchange valve.

• Figur 1 eine Darstellung im Schnitt einer erfinderischen Ventiltriebanordnung,
• Figur 2a und 3b eine erste Ausführungsform eines erfindungsgemäßen Ventiltriebs im Längs- und Querschnitt,
• Figur 3a und 3b eine zweite Ausführungsform eines erfindungsgemäßen Ventiltriebs im Längs- und Querschnitt, und
• Figur 4a, 4b, 4c und 4d eine dritte Ausführungsform eines erfindungsgemäßen Ventiltriebs in einem Längsschnitt und drei Querschnitten.

The invention will be explained in more detail below with reference to the drawing, in which:

• FIG. 1 a representation in section of an inventive valve train assembly,
• FIG. 2a and 3b a first embodiment of a valve gear according to the invention in longitudinal and cross-section,
• Figure 3a and 3b a second embodiment of a valve gear according to the invention in the longitudinal and cross-section, and
• FIGS. 4a, 4b, 4c and 4d a third embodiment of a valve gear according to the invention in a longitudinal section and three cross sections.

FIG. 1 1 shows an embodiment of a valve drive arrangement 10 according to the invention with a plurality of gas exchange valves 12, 14, 16, 18, 20 and 22 arranged in series. In this connection, here a drag lever 66 and the cross section of a valve rod of the respective gas exchange valves 12, 14, 16, 18, 20 and 22 which are arranged in known manner in cylinders 13, 15 and 17. In the present case, two inlet gas exchange valves are assigned to a cylinder of the internal combustion engine. In the present case, the mechanically controllable valve train arrangement 10 has three transmission arrangements 28, 30, 32 and 34, to which two gas exchange valves 12, 14; 16, 18; 20, 22 are assigned. In this case, the transmission arrangements 28, 30 and 32 are mounted on an adjusting shaft 35 in the cylinder head by means of bearing means 36. The bearing means 36 are in the present FIG. 1 merely exemplified for the storage of the adjusting shaft 35.

As will be described in more detail later, each transmission arrangement comprises a first and a second wheel member 40, 42, wherein the first wheel member 40 is operatively connected via a contact roller 44 with a camshaft 46. Both Radorgane 40, 42 are rotatably mounted on the adjusting shaft 35 and are connected to each other geared such that a rotation of the adjusting 35 causes a phase shift between the first and second Radorgan 40, 42 and that a rotational fixation in the same direction oscillating movement of the first and second wheel member 40, 42 causes.

The adjusting shaft 35 is drivable in the present embodiment by a drive member 48 in a known manner. As a drive member 48, a rotary drive is used, which can run both forward and backward. The adjusting shaft 35 can thus be driven in such a way that, depending on the present position, the valve stroke corresponding to the next operating state is selected quickly and precisely. Even angles of rotation of> 360 ° can be realized.

FIG. 2a shows a first embodiment of a mechanically controllable valve drive in longitudinal section. For the sake of clarity, here a valve drive is shown, which acts on a gas exchange valve 12. The adjusting shaft 35 is rotatably mounted in the cylinder head and can by the in FIG. 1 shown drive member 48 are rotated. On the adjusting shaft 35, first, the first wheel member 40 is rotatably mounted. The first wheel member 40 receives the freely rotatable contact roller 44 for the camshaft 46 via a fixed axle 50. Furthermore, the first wheel member 40 is formed as a crown wheel, whose teeth are directed to the second wheel member 42. The first wheel member 40 meshes with a plurality, preferably three planetary gears 54, two of which are shown in the present embodiment and which are each mounted on an axis 56 rotatably connected to the adjusting shaft. These Planet gears 54 mesh over their teeth 58 in turn with the teeth 60 of the likewise formed as a crown wheel second wheel member 42nd Wie der FIG. 2b can be seen, the second wheel member 42, the working contour 62, which is in operative connection with a roller 64 of the drag lever 66.

The operation of the first embodiment is now as follows: With rotationally fixed adjusting shaft 35, the continuously rotating camshaft 46 via a cam 68, the first wheel member 40 in an oscillating about the adjusting shaft 35 movement. As a result, the planetary gears 54 also experience an oscillating movement, as a result of which a movement of the second wheel element 42 which oscillates in the opposite direction to the first wheel element 40 takes place. As a result, the gas exchange valve 12 is then opened on the working contour 62 and closed again in a known manner.

If now the maximum stroke of the gas exchange valve 12 to be changed, takes place by the drive member 48, a rotation of the adjusting 35. By this rotation, the fixed axes 56 of the planet gears 54 are moved in the direction of rotation of the adjusting shaft 35, whereby the phase relationship between the first and the second Radorgan 40th , 42 and accordingly the roller 64 of the finger lever 66 during the opening and closing movement with another portion of the working contour 62 comes into contact.

FIG. 2b shows in cross section the first embodiment according to the invention, in which the gas exchange valve 12 is shown in the closed state. Via a spring element 70, the first wheel member 40 is biased relative to the camshaft 46. The translation between the first wheel member 40 and the planetary gears 54 and between the planet gears 54 and the second wheel member 42 need not be identical be. A translation deviating from the 1: 1 ratio may be advantageous in certain applications.

FIG. 3a shows a longitudinal section of a second embodiment of the invention. Again, the first and the second wheel member 40, 42 are rotatably mounted on the adjusting shaft 35 again, wherein the first wheel member 40, as in the first embodiment, via the fixed axis 50 receives the freely rotatable contact roller 44 for the camshaft 46. The second wheel member 42 may, as in FIG. 2b illustrated, the working contour 62 have. Here, the second wheel member 42 is formed so that the working contour 62 is positioned on an extension piece 72 of the wheel member 42.

The geared connection between the first and second wheel members 40, 42, which in this case are designed as internal gears 74, 76, is made in this second embodiment by a first and a second spur gears 78, 80 which are rotatably mounted on an eccentric 82 are. The eccentric 82 is formed in a known manner on the adjusting shaft 35. Advantageously, the first and second spur gears 78, 80 are integrally formed. In order to effect a phase shift between the first and second wheel members 40, 42, the first and second wheel members 40, 42 and the associated spur gears 78, 80 have a different number of teeth. In the present embodiment, the first wheel member 40 and the associated first spur gear 78 have a smaller diameter and thus a smaller number of teeth than the second Radorgan 42 and the associated second spur gear 80. This is a high reduction between the rotation of the adjusting 35 and the intended phase shift between realized the two Radorganen 40, 42. Via a plate spring 84, which is supported on the bearing 36 of the adjusting shaft 35, and a same direction, sliding profile displacement of the gear connection between the first Radorgan 40 and the first spur gear 78 on the one hand, and between the second Radorgan 42 and the second spur gear 80 on the other hand, the entire geared connection can be biased and backlash be eliminated.

FIG. 3b shows in the present embodiment, the gas exchange valve 12 in the open state with the preset maximum valve lift.

The operation of the second embodiment is now as follows: To represent a preset maximum stroke of the gas exchange valve 12 to be actuated, the adjusting shaft 35 is rotationally fixed. The continuously rotating camshaft 46 displaces the first wheel member 40 with its drive cam 68 in a movement oscillating about the adjusting shaft 35. About the geared connection of the first wheel member 40 with the second wheel member 42, and the second wheel member 42 undergoes a same direction oscillating motion. About the working contour 62 of the endpiece 72 of the second Radorgans 42 then this oscillating motion is transmitted to the roller 64 of the drag lever 66 and thus the gas exchange valve 12 is opened in a known manner with the preset maximum stroke and closed again.

If now the maximum stroke of the gas exchange valve 12 to be changed, takes place here by the drive member 48, a rotation of the adjusting 35. By this rotation, the position of the eccentric 82 is changed and the first and second spur gear 78, 80 rotated in the same direction. Due to the different sizes and numbers of teeth of the gear pairings "first Radorgan - first spur gear" 40, 78 and "second - Radorgan - second spur gear" 42, 80, however, takes place a phase shift between the first Radorgan 40 and the second Radorgan 42. Accordingly, the nosepiece 72 of the second wheel member 42 also becomes a desired angle rotated so that the roller 64 of the finger lever 66 during the opening and closing movement with another portion of the working contour 62 of the endpiece of the second wheel member 42 comes into contact.

FIG. 4a shows a longitudinal section of a third embodiment of the invention. This embodiment describes a particularly compact solution, since the entire transmission arrangement is to be stored only about two axes 35, 46. A particular advantage is that the position of the camshaft with respect to a valve train with a fixed maximum stroke does not have to be changed. Also, this unit can be easily and inexpensively mounted as a verifiable unit, since all components are stored in the two axes 35,46.

As in the embodiment according to the FIGS. 3a and 3b are a first and a second wheel member 40, 42 are provided, which are rotatably mounted on the adjusting shaft 35. The first and second wheel member 40, 42 are designed as internal gears 74, 76 of different size and number of teeth, which are connected via two spur gears 78, 80 geared together. The spur gears 78, 80 are rotatably mounted as in the second embodiment on an eccentric 82 of the adjusting shaft 35 and corresponding to the meshing internal gears 74, 76 have a different size and number of teeth.

The first wheel member 40 also has a fixed axle 50 (see FIG. 4b ), on which the contact roller 44 for the drive cam 68, which here has a different shape than in the preceding embodiments, is rotatably mounted.

The second wheel member 42 also has an outer toothing 86, which is in operative connection with the external toothing 88 of a Auslenkorgans 90, which in turn is rotatably mounted on the camshaft 46 (see also Figure 4c ). In the present case, the deflection element 90 has two deflection cams 92, which describe a working contour and which act on the roller 64 of a drag lever 66 of a gas exchange valve 12 in a known manner. The drag levers 66 are in turn rotatably mounted on the adjusting shaft 35 (see FIG. 4d ).

Via a plate spring 84 which is supported on the bearing 36 of the camshaft 46 and on Auslenkorgan 90 in the axial direction, and the same direction, sliding profile displacements of the gear connection between external teeth 88 of the Auslenkorgans 90 and outer teeth 86 of the second Radorgans 42, between the second Radorgan 42 and the second spur gear 80, as well as between the first wheel member 40 and the first spur gear 78, the entire geared connection can be biased and the backlash be eliminated.

The operation of the third embodiment is now as follows: With a preset maximum stroke of the gas exchange valve 12 to be actuated, the adjusting shaft 35 is rotationally fixed. The continuously rotating camshaft 46 displaces the first wheel member 40 with its drive cam 68 in a movement oscillating about the adjusting shaft 35. About the geared connection of the first wheel member 40 with the second wheel member 42 and the second wheel member 42 undergoes a like-minded oscillating movement. About the external gear teeth 86 of the second wheel member 42 then this oscillating movement is transmitted in an opposite, oscillating movement of the Auslenkorgans 90. By Auslenknocken 92, which acts on the drag lever 66, the gas exchange valve 12 is then opened in a known manner with the preset maximum stroke and closed again.

If now the maximum stroke of the gas exchange valve 12 to be changed, takes place here by the drive member 48, a rotation of the adjusting shaft 35. By this rotation, the position of the Exzenters 82 changed and thus also the first and second spur gear 78, 80 rotated in the same direction. Due to the different sizes and numbers of teeth of the gear pairings "first wheel member - first spur gear" 40, 78 and "second - wheel member - second spur gear" 42, 80, a phase shift between the first wheel member 40 and the second wheel member 42 takes place. Accordingly, the deflection member 90 is rotated by a desired angle so that the roller 64 of the finger lever 66 during the opening and closing movement with another portion of the Auslenknockens 92 contacts.

Particular advantages arise in this embodiment according to Fig. 4 in that due to the translation between the outer teeth 86 of the Radorgans 42 and the outer teeth 88 of the Auslenkorgans 90, the oscillating movement of the Auslenkorgans 90 sweeps over a larger angular range than it is predetermined by the first wheel member 40. This results in more favorable force conditions on the working contour of the Auslenknockens 92nd

All described embodiments can be designed so that the deflection member performs an oscillating movement with only a small tilt angle. In this case, only a part of the entire circumference of the deflection element is used to vary the maximum valve lifts in the range between zero stroke and full stroke. It is therefore possible to apply a further and different working contour to the remaining part of the circumference. These contours can be e.g. be purposefully shut down individual gas exchange valves of a cylinder to ensure a more precise flow control and trigger a demand-based charge movement in the cylinder, or shut down all valves of a cylinder to represent a cylinder shutdown.

Claims (11)

1. A mechanically controllable valve drive having a gas exchange valve (12) on which a transmission arrangement acts directly or indirectly by means of a working contour (62; 92), wherein the transmission arrangement is mounted in a movable manner in the cylinder head by bearing means, and wherein the transmission arrangement is operatively connected to a valve stroke adjusting device and to a camshaft (46), wherein the valve stroke adjusting device has a rotatable adjusting shaft (35) such that different maximum strokes can be set, the transmission arrangement having a first and a second wheel element (40, 42), wherein the first wheel element (40) is operatively connected to the camshaft (46) and the second wheel element (42) acts directly or indirectly on the gas exchange valve (12), wherein the two wheel elements (40, 42) are rotatably mounted on the adjusting shaft (35) and have a toothing, in such a way that the first and the second wheel element (40, 42) are in geared connection with one another such that a rotation of the adjusting shaft (35) effects a phase shift between the first and the second wheel element (40, 42) and such that rotary fixing is effective to generate an oscillating movement of the first and second wheel elements (40, 42), characterized in that the toothing is realized such that rotation of the adjusting shaft (35) causes the phase shift.
2. The mechanically controllable valve drive according to claim 1, characterized in that the first wheel element (40) is biased relative to the camshaft (46) by a spring element (70).
3. The mechanically controllable valve drive according to claim 1 or 2, characterized in that the first and the second wheel element (40, 42) are formed as mutually confronting crown gears and that the gear connection is realized via at least one planetary gear (54), each planetary gear (54) being supported on an axis connected to the adjusting shaft (35) for common rotation therewith.
4. The mechanically controllable valve drive according to claim 1, characterized in that the first and the second wheel element (40, 42) are formed as internal gears, wherein the first wheel element (40) has a different inner diameter with a different number of teeth than the second wheel element (42), and that the adjustment shaft (35) comprises an eccentric (82) having a first and a second spur gear (78, 80) rotatably supported thereon which are coupled to each other in a torsionally rigid manner and are in engagement with the first and respectively the second wheel element (40, 42) and thus form the gear connection.
5. The mechanically controllable valve drive according to claim 4, characterized in that the first and the second spur gears (78, 80) are formed as one part.
6. The mechanically controllable valve drive according to claim 4 or 5, characterized in that the second wheel element (42) is rotatably supported on the peripheral surface of the first wheel element (40).
7. The mechanically controllable valve drive according to any one of the preceding claims, characterized in that the first wheel element (40) comprises a contact roll (44) for the camshaft (46).
8. The mechanically controllable valve drive according to any one of the preceding claims, characterized in that the second wheel element (42) comprises a working contour (62).
9. The mechanically controllable valve drive according to any one of claims 4 to 7, characterized in that the second wheel element is in geared connection with a deflecting member (90) comprising said working contour (62), said deflecting member (90) being rotatably and concentrically supported on the camshaft (46).
10. The mechanically controllable valve drive according to claim 9, characterized in that a drag lever (66) is rotatably supported on the adjusting shaft (35).
11. A mechanically controllable valve drive arrangement comprising a plurality of serially arranged gas exchange valves assigned to a plurality of cylinders, characterized in that each cylinder has assigned thereto a mechanically controllable valve drive according to any one of claims 1 to 10, wherein each gas exchange valve has assigned thereto a respective working contour which directly or indirectly acts on the gas exchange valve.

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